ForestWang wrote:is there a branch with 91bootstrap for the application without OS, or for uc/OS like?

I know nothing about uC/OS, so I'm not sure what you mean by "application without OS" (do you mean a standalone program?) or "for uc/OS like" (bad grammar?).
Latest versions of AT91Bootstrap can load U-Boot, the Linux or Android kernel or a standalone program (intended for Softpack examples).
If you learn how to boot an uc/OS application, then you can try to use the standalone configuration or customize AT91Bootsrtap.

ForestWang wrote:is there a branch with 91bootstrap for the application without OS, or for uc/OS like?

I know nothing about uC/OS, so I'm not sure what you mean by "application without OS" (do you mean a standalone program?) or "for uc/OS like" (bad grammar?).
Latest versions of AT91Bootstrap can load U-Boot, the Linux or Android kernel or a standalone program (intended for Softpack examples).
If you learn how to boot an uc/OS application, then you can try to use the standalone configuration or customize AT91Bootsrtap.

None of them. The standalone-program configuration does not have a configuration file.
You will have to choose a config file that is close to what you need. Perform the `make xxx_defconfig', and then customize the configuration with a `make menuconfig`. The "Image Loading Strategy" and "Demo Application Image Storage Setup" are the salient selections.